The present invention relates to a rate adjusting method of a mechanical type timepiece.
The invention particularly relates to a method of adjusting a rate of a mechanical timepiece by attaching a weight to a portion of a balance wheel or removing a portion of the balance wheel in a movement of a mechanical type timepiece.
In a conventional mechanical type timepiece, as shown in FIG. 16 and FIG. 17, a movement (machine body) 1100 of a mechanical type timepiece is provided with a main plate 1102 constituting a base plate of the movement. A winding stem 1110 is rotatably integrated to a winding stem guide hole 1102a of the main plate 1102. A dial 1104 (shown by imaginary lines in FIG. 17) is attached to the movement 1100.
Generally, in both sides of the main plate, a side thereof having the dial is referred to as xe2x80x9cback sidexe2x80x9d of the movement and a side opposed to the side having the dial is referred to as xe2x80x9cfront sidexe2x80x9d of the movement. A train wheel integrated to the xe2x80x9cfront sidexe2x80x9d of the movement is referred to as xe2x80x9cfront train wheelxe2x80x9d and a train wheel integrated to the xe2x80x9cback sidexe2x80x9d of the movement is referred to as xe2x80x9cback train wheelxe2x80x9d.
By a switch apparatus including a setting lever 1190, a yoke 1192, a yoke spring 1194 and a setting lever jumper 1196, a position of the winding stem 1110 in an axis line direction thereof is determined. A winding pinion 1112 is rotatably provided to a guide shaft portion of the winding stem 1110. When the winding stem 1110 is rotated in a state in which the winding stem 1110 is disposed at a first winding stem position (0-th stage) mostly proximate to an inner side of the movement along a rotational axis line, the winding pinion 1112 is rotated via rotation of a clutch wheel. A crown wheel 1114 is rotated by rotation of the winding pinion 1112. A ratchet wheel 1116 is rotated by rotation of the crown wheel 1114. By rotating the ratchet wheel 1116, a mainspring 1122 contained in a barrel complete 1120 is wound up. A center wheel and pinion 1124 is rotated by rotation of the barrel complete 1120. An escape wheel and pinion 1130 is rotated via rotation of a fourth wheel and pinion 1128, a third wheel and pinion 1126 and the center wheel and pinion 1124. The barrel complete 1120, the center wheel and pinion 1124, the third wheel and pinion 1126 and the fourth wheel and pinion 1128 constitute a front train wheel.
An escapement and speed control apparatus for controlling rotation of the front train wheel includes a balance with hairspring 1140, the escape wheel and train 1130 and a pallet fork 1142. The balance with hairspring 1140 includes a balance stem 1140a, a balance wheel 1140b and a hairspring 1140c. Based on rotation of the center wheel and pinion 1124, an hour pinion 1150 is simultaneously rotated. A minute hand 1152 attached to the hour pinion 1150 displays xe2x80x9cminutexe2x80x9d. The hour pinion 1150 is provided with a slip mechanism relative to the center wheel and pinion 1124. Based on rotation of the hour pinion 1150, an hour wheel 1154 is rotated via rotation of a minute wheel. An hour hand 1156 attached to the hour wheel 1154 displays xe2x80x9chourxe2x80x9d.
The barrel complete 1120 is supported by the main plate 1102 and a barrel bridge 1160 rotatably thereto. The center wheel and pinion 1124, the third wheel and pinion 1126, the fourth wheel and pinion 1128 and the escape wheel and pinion 1130 are supported by the main plate 1102 and a train wheel bridge 1162 rotatably thereto. The pallet fork 1142 is supported by the main plate 1102 and a pallet bridge 1164 rotatably thereto. The balance with hairspring 1140 is supported by the main plate 1102 and a balance with hairspring bridge 1166 rotatably thereto.
The hairspring 1140c is a thin plate spring in a helical (spiral) mode having a plural turn number. An inner end portion of the hairspring 1140c is fixed to a hairspring holder 1140d fixed to the balance stem 1140a and an outer end portion of the hairspring 1140c is fixed by screw fastening via a hairspring support 1170a attached to a stud support 1170 fixed to the balance with hairspring bridge 1166.
A regulator 1168 is rotatably attached to the balance bridge 1166. A hairspring bridge 1168a and a hairspring rod 1168b are attached to the regulator 1168. A portion of the hairspring 1140c proximate to the outer end portion is disposed between the hairspring bridge 1168a and the hairspring rod 1168b. 
Generally, according to a conventional representative mechanical type timepiece, mainspring torque is reduced as a duration time period elapses by rewinding the mainspring from a state in which the mainspring is completely wound up (fully wound state). For example, the mainspring torque is about 27 gxc2x7cm in the fully wound state, becomes about 23 gxc2x7cm after 20 hours has elapsed from the fully wound state and becomes about 18 gxc2x7cm after 40 hours has elapsed from the fully wound state.
Generally, according to a conventional representative mechanical type timepiece, when mainspring torque is reduced, a swing angle of the balance with hairspring is also reduced. For example, when the mainspring torque falls in a range of 25 through 28 gxc2x7cm, the swing angle of the balance with hairspring is about 240 through 270 degrees and when the mainspring torque falls in a range of 20 through 25 gxc2x7cm, the swing angle of the balance with hairspring is about 180 through 240 degrees.
Here, xe2x80x9cinstantaneous ratexe2x80x9d or xe2x80x9cratexe2x80x9d is referred to as xe2x80x9cvalue indicating gaining or losing of a mechanical type timepiece when 1 day has elapsed when assuming that the mechanical type timepiece is left for 1 day while maintaining state or environment of the swing angle of the balance with hairspring or the like when the rate is measuredxe2x80x9d. The xe2x80x9cratexe2x80x9d is designated by notation H.
For example, although in a conventional representative mechanical type timepiece, when a swing angle of a balance with hairspring falls in a range of about 200 through 240 degrees, the instantaneous rate is about 0 through 5 seconds/day (gaining of about 0 through 5 seconds per day), when the swing angle of the balance with hairspring is about 170 degrees, the instantaneous rate becomes about xe2x88x9220 seconds/day (losing of about 20 seconds per day).
Generally, according to the conventional mechanical type timepiece, with elapse of a duration time period by rewinding the mainspring from a fully wound state, the mainspring torque is reduced, the swing angle of the balance with hairspring is also reduced and accordingly, the instantaneous rate is retarded. Therefore, according to the conventional mechanical type timepiece, by estimating a delay of the timepiece after the duration time period has elapsed for 24 hours, the instantaneous rate when the main spring is brought into the fully wound state, is previously increased, and is previously adjusted such that the xe2x80x9cratexe2x80x9d indicating gaining of the timepiece or losing of the timepiece per day becomes positive.
In a mechanical type timepiece, when assuming a state of attaching a dial, xe2x80x9cflat attitudexe2x80x9d in which the dial becomes horizontal and xe2x80x9cvertical attitudexe2x80x9d in which the dial becomes vertical are defined.
Further, according to the mechanical type timepiece, when the state attached with the dial is assumed, a direction directed from the center of the mechanical timepiece to 12 o""clock indicator of the dial is referred to as xe2x80x9c12 o""clock directionxe2x80x9d, a direction directed from the center of the mechanical type timepiece to 3 o""clock indicator of the dial is referred to as xe2x80x9c3 o""clock directionxe2x80x9d, a direction directed from the center of the mechanical type timepiece to 6 o""clock indicator of the dial is referred to as xe2x80x9c6 o""clock directionxe2x80x9d and a direction directed from the center of the mechanical type timepiece to 9 o""clock indicator of the dial is referred to as xe2x80x9c9o""clock directionxe2x80x9d (refer to FIG. 16).
Further, in the mechanical type timepiece, when assuming a state in which the dial is attached and the dial becomes vertical, an attitude in which the 12 o""clock indicator of the dial is disposed on an upper side is referred to as xe2x80x9cattitude of 12 o""clock upperxe2x80x9d, an attitude in which 3 o""clock indicator of the dial is disposed on the upper side is referred to as xe2x80x9cattitude of 3 o""clock upperxe2x80x9d, an attitude in which 6 o""clock indicator of the dial is disposed on the upper side is referred to as xe2x80x9cattitude of 6 o""clock upperxe2x80x9d and an attitude in which 9 o""clock indicator of the dial is disposed on the upper side is referred to as xe2x80x9cattitude of 9 o""clock upperxe2x80x9d.
Further, it is known in the mechanical type timepiece that measured values of the xe2x80x9cratexe2x80x9d differ with regard to four attitudes of the xe2x80x9cattitude of 12 o""clock upperxe2x80x9d, xe2x80x9cattitude of 3 o""clock upperxe2x80x9d, xe2x80x9cattitude of 6 o""clock upperxe2x80x9d and xe2x80x9cattitude of 9 o""clock upperxe2x80x9d. Therefore, according to the mechanical type timepiece, the xe2x80x9cratexe2x80x9d is measured with respect to the four attitudes and the rate of the mechanical type timepiece is adjusted such that the respective measured values of the xe2x80x9cratexe2x80x9d satisfy a predetermined standard.
In the following explanation, the xe2x80x9crate when the mechanical type timepiece is disposed in the attitude of 12 o""clock upperxe2x80x9d is referred to as xe2x80x9c12 upper ratexe2x80x9d, the xe2x80x9crate when the mechanical type timepiece is disposed in the attitude of 3 o""clock upperxe2x80x9d is referred to as xe2x80x9c3 upper ratexe2x80x9d, the xe2x80x9crate when the mechanical type timepiece is disposed in the attitude of 6 o""clock upperxe2x80x9d is referred to as xe2x80x9c6 upper ratexe2x80x9d and the xe2x80x9crate when the mechanical type timepiece is disposed in the attitude of 9 o""clock upperxe2x80x9d is referred to as xe2x80x9c9 upper ratexe2x80x9d.
Further, the xe2x80x9c12 upper ratexe2x80x9d is designated by notation Htw, the xe2x80x9c3 upper ratexe2x80x9d is designated by notation Hth, the xe2x80x9c6 upper ratexe2x80x9d is designated by notation Hsi and the xe2x80x9c9 upper ratexe2x80x9d is designated by notation Hni.
Conventionally, in adjusting the rate of such a mechanical type timepiece, the balance with hairspring 1140 is removed by manual operation from the movement (machine body) 1100 of the mechanical type timepiece which has been assembled once, a portion of the balance wheel is cut off by manual operation and the balance with hairspring 1140 is assembled again in the movement (machine body) 1100. Therefore, firstly, the rate is measured in the movement (machine body) 1100 of the mechanical type timepiece which has been assembled once, a portion of the balance wheel is cut off and thereafter, the rate is measured in the movement (machine body) 1100 reassembled with the balance with hairspring 1140.
Therefore, according to the conventional method of adjusting the rate of the mechanical type timepiece, operation of disassembling and assembling the balance with hairsprings 1140 is complicated, operation of measuring the rate is also complicated and there poses a problem in which enormous time and labor is taken in adjusting the rate.
Furthermore, according to the conventional method of adjusting the rate of the mechanical type timepiece, there is included a step of cutting a portion of the balance wheel by manual operation and therefore, it is difficult to adjust the rate with high accuracy.
Hence, it is an object of the invention to provide a method capable of adjusting a rate of a mechanical type timepiece without removing a balance with hairspring from a movement (machine body) of the mechanical type timepiece.
It is a further object of the invention to provide a method capable of adjusting a rate of a mechanical type timepiece in a short period of time and with extremely high accuracy.
The present invention is a rate adjusting method of a mechanical type timepiece comprising a movement constituted to include a mainspring constituting a power source of the mechanical type timepiece, a front train wheel rotated by a rotational force in rewinding the mainspring and an escapement and speed control apparatus for controlling rotation of the front train wheel, the escapement and speed control apparatus including a balance with hairspring alternately repeating right-hand rotation and left-hand rotation, an escape wheel and pinion rotated based on rotation of the front train wheel and a pallet fork for controlling rotation of the escape wheel and pinion based on operation of the balance with hairspring and the balance with hairspring including a hairspring, a balance stem and a balance wheel.
The rate adjusting method of a mechanical type timepiece according to the invention is characterized in including:
(a) a stage of assembling the movement of the mechanical type timepiece;
(b) a stage of measuring rates with regard to a plurality of xe2x80x9cvertical attitudesxe2x80x9d in a state in which the assembled movement is arranged in xe2x80x9cvertical attitudexe2x80x9d;
(c) a stage of calculating the magnitude and the direction of an attitude difference vector based on a result of measuring the rates in the stage (b);
(d) a stage of calculating a weight amount to be added to the balance wheel or a weight amount to be removed from the balance wheel and calculating a position of the balance wheel to be added with the weight amount or to be removed of the weight amount based on a result of calculating the magnitude and the direction of the attitude difference vector in the stage (c); and
(e) a stage of adding or removing the weight amount to or from the balance wheel based on a result of calculating the weight amount to be added to the balance wheel or to be removed from the balance wheel and calculating the position of the balance wheel to be added with the weight amount or to be removed of the weight amount in the stage (d).
According to the rate adjusting method of a mechanical type timepiece of the invention, it is preferable that the rates are measured in the stage (b) with respect to the four xe2x80x9cvertical attitudesxe2x80x9d of xe2x80x9cattitude of 12 o""clock upperxe2x80x9d, xe2x80x9cattitude of 3 o""clock upperxe2x80x9d, xe2x80x9cattitude of 6 o""clock upperxe2x80x9d, and xe2x80x9cattitude of 9 o""clock upperxe2x80x9d.
By using the method of the invention, the rate of the mechanical type timepiece can simply be adjusted without removing the balance with hairspring from the movement of the mechanical type timepiece.
Further, by using the method of the invention, the rate of the mechanical type timepiece can accurately be adjusted in a short period of time and with extremely high accuracy.
Further, according to the rate adjusting method of a mechanical type timepiece of the invention, it is preferable that the stage (d) includes a stage of calculating the weight amount to be added to the balance wheel and calculating the position of the balance wheel to be added with the weight amount based on the result of calculating the magnitude and the direction of the attitude difference vector at the stage (c), and the stage (e) includes a stage of attaching the weight amount on a surface of the balance wheel by using an ink jet projecting apparatus based on the result of calculating the weight amount to be added to the balance wheel and calculating the position of the balance wheel to be added with the weight amount in the stage (d).
In this way, by using the ink jet projecting apparatus, the weight amount can accurately be attached to the surface of the balance wheel in a short period of time and with extremely high accuracy.
Further, according to the rate adjusting method of a mechanical type timepiece of the invention, it is preferable that the stage (d) includes a stage of calculating the weight amount to be removed from the balance wheel and the position of the balance wheel to be removed of the weight amount based on the result of calculating the magnitude and the method of the attitude difference vector in the stage (c), and the stage (e) includes a stage of removing the weight amount from the balance wheel by using a laser emitting apparatus based on the result of calculating the weight amount to be removed from the balance wheel and calculating the position of the balance wheel to be removed of the weight amount in the stage (d).
In this way, by using the laser projecting apparatus, the weight amount can accurately be removed from the balance wheel in a short period of time and with extremely high accuracy.
Further, according to the rate adjusting method of the mechanical type timepiece of the invention, it is preferable that the stage (c) includes a stage of calculating the magnitude and the direction of the attitude difference vector with respect to a plurality of swing angles of the balance with hairspring.
By using the rate adjusting method including such a stage, the magnitude and the direction of the attitude difference vector can accurately be calculated.